Long before Stephen Hawking and his Brief History of Time , there was Plato and Timaeus. It develops, among others, (in the words of the astronomer Timaeus), his theory of the formation of the Universe (the Cosmos in Greek), that is to say its cosmology. He summons a Creator (his famous good « Demiurge » without desire), whose objective was, it seems, to create a universe in his image. Plato differs from the Christian theory, since he assumes a « pre-existing » initial chaos. The world in Plato is not created ex nihilo. In this initial chaos, there are in particular, mixed well in a sacred disorder, earth, fire, air and water. Plato does not explain from where come these four substances, no doubt, in his mind, eternal. The Demiurge, mathematician at times, determines the ideal proportions of each element (this idea is inspired by the Pythagorean who conceived the universe as organized around integer numbers) and shapes the earth. Then He forms a sphere, perfect geometric shape and flattens it at the poles (Plato was right!). Christians forget Plato when they burn all those who will design the land other than in the form of a flat disk.
God, always, because of the geometry. Quote Plato Timaeus
He puts the Earth at the center of the universe (geocentric) and puts it into rotational movement on itself. Then he turned the seven heavenly bodies (moon, sun and five planets known at the time) around a well-defined plan. This geocentric model will pollute science until Copernicus (sixteenth century)!
A digression on heliocentrism in ancient Greece
Philolaus (fifth century BC) was the first to dare to say that the earth was not the center point of the Universe, busy, he said, by a sort of « primordial fire » whose light would be reflected on earth by the sun. Plato forma disciples Aristotle and Heraclides of Pontus: it (IV century BC) took a step further by claiming that Venus and Mercury revolved around the sun. Not until Aristarchus of Samos (IV century BC) to put the sun in the center. Aristarchus was attacked from all sides for breaking the taboo Platonic and having thus guilty of lese majeste.
According to Plato, the distance between the earth and each of the planets are also determined with integer numbers.
The demiurge wants a sustainable world. It therefore creates time. Announcing Einstein and relativity principle, Plato does not hesitate to link the time and space. Time is the origin of the movement, particularly that of the Universe.
Time moving image of immobile eternity. Quote Plato Timaeus
Plato had already distinguished (in the myth of the Cave including) the sensible world (accessible through our senses) and the world of ideas (accessible through our thought). He now sets this aging and disappears with the death of what is timeless and reporting to the divine. The world of ideas is part of the second category. The man therefore encloses a divine plot in him: the soul. Conversely, the universe is an animal endowed with intelligence and a core (which is placed in the center).
The Soul of the world is the principle of motion ordered the universe. This is the general cause of life, and life is always manifested by regularly ordered movement toward a certain end. Quote Plato Timaeus
The hierarchy of species
The only immortal is the Creator. Then come the Half-Gods (half immortal) who themselves created the 4 mortal races :
- men ;
- birds (winged);
- fishs (aquatic race);
- terrestrial animals.
Halfway between God and animals. Men has a fraction of immortality (its soul) and a body destined to disappear with death.
We find in the Timaeus a lot of ideas that will be recycled by the Christians. The concept of God the Creator conceiving man in his image, soul (noble part of man) immortal, distinguished from the mortal body (ignoble part). Of course, Plato had little information to build its cosmogony and therefore forgive him his simplistic view of the universe.